1. Field of the Invention
The invention relates to submarine underwater countermeasure assemblies and is directed more particularly to an improved countermeasure vehicle.
2. Description of the Prior Art
In FIG. 1, there is shown a typical submarine countermeasure apparatus 20. The apparatus 20 includes a launch tube 22 which, in operation, is disposed outboard of the submarine pressure hull (not shown). A countermeasure vehicle 24 is housed in the launch tube 22 and includes an array assembly 26 and a tailcone assembly 28. The array assembly 26 is protected by a surrounding sabot 30. Disposed in the launch tube 22 is a ram plate 32 and a gas generator 34. The launch tube is closed by a forward tube cover 36 and an after tube cover 38.
In operation, the gas generator 34 is activated by an electrical pulse from the submarine fire control system and generates sufficient gas pressure to move the ram plate 32 forwardly. The ram plate 32 pushes the countermeasure vehicle 24 forwardly, breaking away the forward tube cover 36 and launching the countermeasure vehicle 24 from the launch tube 22. In short order, the sabot 30 disengages from around the array assembly 26 and the array assembly is deployed.
The tail cone assembly 28 includes a propulsion propeller assembly 40, and the countermeasure vehicle 24 houses a motor 42 (FIG. 2) which drives the propeller assembly to position the countermeasure vehicle 24 in a vertical column of water with the propeller oriented towards the surface.
It has been found that upon launch of the vehicle 24, a combination of a high velocity launch, high maneuvering speed of the submarine, and strong cross flows on the vehicle 24 hull from launching perpendicular to the submarine hull, can subject propeller blades 44 to pressures and bending movements sufficient to damage the propellers and the vehicle tail section. While providing some protection, the currently used tailcone assembly 28 is not sufficient to protect the propeller from damage under severe launching conditions. Damaged propellers can affect the ability of the countermeasure to hover at a selected depth in the water column, and thereby cause mission failure which places the submarine in a state of increased danger.
Accordingly, there is a need for an improved tailcone assembly which can withstand and survive the aforesaid launch conditions and which provides improved propeller protection against severe bending moments.